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EP0794462A2
Expired / Lapsed
EP
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Independently controllable shutters and variable area apertures for off axis illumination
Assignee: Infineon Technologies AG En Toshi KK
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Filing: 1997-02-20
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Granted: —
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Expires: 2017-02-20
Abstract
Abstract Apertures to vary the size and shape of the aperture area without the need to change the whole aperture plate in off axis lithography. The off axis illumination apertures allow the size and shape of apertures to be changed without having to change the aperture plates for each step in the lithographic process. The aperture plate (40) is fitted with simple shutter mechanisms (41-44) that allow ready adjustment of the aperture openings.
Inventors
- 👤 Bernhard L. Poschenrieder
- 👤 Takashi Sato
- 👤 Tsukasa Azuma
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 11:33
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70058; G03F7/70091; G03F7/701
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
128 words
An off axis illumination system for photolithographic exposure of a photosensitive film on a device substrate in the manufacture of semiconductor devices comprising: a source of light for exposing the photosensitive film; a photomask which contains a magnified image of pattern etched into a metallic layer, said photomask being interposed between the source of light and the photosensitive film to be exposed; a lens system between the photomask and the resist for reducing the size of an illuminated image for patterning into the photosensitive film on the device substrate; and an aperture plate positioned between the source of light and the photomask, said aperture plate having independently controllable shutters to provide variable area apertures, each exposure being separately optimized by adjusting the apertures for a specific lithographic step.
Claim 2
Dependent Claim
74 words
The off axis illumination system for photolithographic exposure of a photosensitive film on a device substrate in the manufacture of semiconductor devices as recited in claim 1 wherein said aperture plate has a plurality of apertures equally spaced radially about a center of the aperture plate and the independently controllable shutters comprise a butterfly-shaped shutter pivotally mounted at the center of the aperture plate and movable to occlude or partially occlude diametrically opposite apertures.
Claim 3
Dependent Claim
80 words
The off axis illumination system for photolithographic exposure of a photosensitive film on a device substrate in the manufacture of semiconductor devices as recited in claim 1 wherein said aperture plate has a plurality of apertures equally spaced radially about a center of the aperture plate and the independently controllable shutters comprise a plurality of shutters, one for each of said apertures, pivotally mounted adjacent respective apertures and independently movable to occlude or partially occlude respective ones of said apertures.
Claim 4
Dependent Claim
47 words
The off axis illumination system for photolithographic exposure of a photosensitive film on a device substrate in the manufacture of semiconductor devices as recited in claim 3 wherein said shutters have a plurality of blades which may be rotated to occlude or partially occlude a respective aperture.
Claim 5
Dependent Claim
53 words
The off axis illumination system for photolithographic exposure of a photosensitive film on a device substrate in the manufacture of semiconductor devices as recited in claim 3 wherein said shutters are disks having at least one radially extending slot which may be rotated into registry with a corresponding aperture in said aperture plate.
Claim 6
Dependent Claim
60 words
The off axis illumination system for photolithographic exposure of a photosensitive film on a device substrate in the manufacture of semiconductor devices as recited in claim 3 wherein said shutters are disks having at least one aperture radially displaced from a center of the disk and which may be rotated into registry with a corresponding aperture in said aperture plate.
Claim 7
Dependent Claim
71 words
The off axis illumination system for photolithographic exposure of a photosensitive film on a device substrate in the manufacture of semiconductor devices as recited in claim 6 wherein the disks each have a plurality of apertures of different sizes each radially displaced from the center of the disk, each said aperture partially occluding in different amounts a corresponding aperture on said aperture plate when rotated into registry with the corresponding aperture.
Claim 8
Dependent Claim
36 words
The off axis illumination system for photolithographic exposure of a photosensitive film on a device substrate in the manufacture of semiconductor devices as recited in claim 7 wherein the apertures on the disks are circular holes.
Claim 9
Dependent Claim
36 words
The off axis illumination system for photolithographic exposure of a photosensitive film on a device substrate in the manufacture of semiconductor devices as recited in claim 7 wherein the apertures on the disks are rectangular holes.
Claim 10
Dependent Claim
33 words
The off axis illumination system for photolithographic exposure of a photosensitive film on a device substrate in the manufacture of semiconductor devices as recited in claim 3 wherein said shutters are iris apertures.
References Cited (Backward Citations)
No citation records indexed.
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